Two cases of dual origin left vertebral arteries with non-convergence

Kimberly A Congdon*, Nicole Cl

Abstract

In typical human anatomy, the vertebral arteries (VA) originate from the subclavian arteries (SCA) and enter the transverse foramen of the sixth cervical vertebra (C6). The reported frequency of deviations vary, but the clinical significance of a more medial location of aberrant LVAs result in a need to understand their frequency in the population, as well as any coexisting vascular variations. Here we reported 2 cases of variant left vertebral arteries that entered the transverse foramen of the C4 vertebra and continued to the brain. Both presented with a second vessel entering the C6 transverse foramen, suggesting a dual origin of the left vertebral artery, but in neither case did the two vessels converge. These findings suggest a higher frequency of occurrence of this anatomical variation, and demonstrate the continued importance of cadaver-based anatomical study.